Ruvinsky I, Gibson-Brown J J
Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
Development. 2000 Dec;127(24):5233-44. doi: 10.1242/dev.127.24.5233.
Two sets of paired appendages are a characteristic feature of the body plan of jawed vertebrates. While the fossil record provides a good morphological description of limb evolution, the molecular mechanisms involved in this process are only now beginning to be understood. It is likely that the genes essential for limb development in modern vertebrates were also important players during limb evolution. In recent years, genes from a number of gene families have been described that play important roles both in limb induction and in later patterning processes. These advances facilitate inquiries into several important aspects of limb evolution such as their origin, position along the body axis, number and identity. Integrating paleontological, developmental and genetic data, we propose models to explain the evolution of paired appendages in vertebrates. Whereas previous syntheses have tended to focus on the roles of genes from a single gene family, most notably Hox genes, we emphasize the importance of considering the interactions among multiple genes from different gene families for understanding the evolution of complex developmental systems. Our models, which underscore the roles of gene duplication and regulatory 'tinkering', provide a conceptual framework for elucidating the evolution of serially homologous structures in general, and thus contribute to the burgeoning field seeking to uncover the genetic and developmental bases of evolution.
两组成对的附肢是有颌脊椎动物身体结构的一个特征。虽然化石记录提供了关于肢体进化的良好形态学描述，但这一过程中涉及的分子机制直到现在才开始被理解。现代脊椎动物肢体发育所必需的基因在肢体进化过程中可能也是重要因素。近年来，已经描述了许多基因家族中的基因，它们在肢体诱导和后期模式形成过程中都发挥着重要作用。这些进展有助于探究肢体进化的几个重要方面，如它们的起源、沿身体轴的位置、数量和特征。整合古生物学、发育学和遗传学数据，我们提出模型来解释脊椎动物成对附肢的进化。尽管之前的综合研究倾向于关注单个基因家族（最显著的是Hox基因）的作用，但我们强调，为了理解复杂发育系统的进化，考虑来自不同基因家族的多个基因之间的相互作用非常重要。我们的模型强调了基因复制和调控“微调”的作用，为阐明一般情况下系列同源结构的进化提供了一个概念框架，从而为这个新兴领域做出了贡献，该领域致力于揭示进化的遗传和发育基础。
